Higher-Order Leaky-Mode Bessel-Beam Launcher

Walter Fuscaldo (1) , Guido Valerio (2) , Alessandro Galli (3) , Ronan Sauleau (1) , Anthony Grbic , Mauro Ettorre (1)

1 IETR - Institut d'Électronique et des Technologies du numéRique
2 UPMC - Université Pierre et Marie Curie - Paris 6
3 DIET - Dipartimento di Ingegneria dell'Informazione, Elettronica e Telecomunicazioni [Roma]

We present a Bessel-beam launcher based on a leaky radial waveguide consisting of a capacitive sheet over a ground plane that supports higher-order leaky modes. A propagating Bessel beam is generated above the radiating waveguide. The Bessel beam is transverse-magnetic (TM) polarized with a vertical component of electric field that is a zeroth-order Bessel function of the first kind. A higher-order leaky-wave mode is used to reduce losses at millimeter waves and, at the same time, avoid the thin dielectric layers used in previously proposed lower order leakywave Bessel launchers. Closed-form design equations are provided for the proposed structure. In addition, the operating bandwidth of the launcher is defined using dispersion analysis. Near-field measurements of a prototype operating in the frequency range 38- 39.5 GHz validate the concept. The measured launcher generates a Bessel beam with a stable spot size of about 4.3 mm (0.57 λ) over a nondiffractive range of about 16.4 mm (2.2 λ), within about a 4% fractional bandwidth

Keywords: Impedance; high-order modes; higher-order leaky-wave mode; higher-order leaky modes; electromagnetic launchers; frequency 38 GHz to 39.5 GHz; operating bandwidth; electric field; dispersion analysis; Dispersion; capacitive sheet; Bessel beams; Bessel-beam launcher; Bandwidth; artificial surface; leaky waves; millimeter waves; Apertures; millimetre wave propagation; near-field focusing; near-field measurements; leaky radial waveguide; Approximation methods; zeroth-order Bessel function; transverse-magnetic; Prototypes; propagating Bessel beam; Index Terms-Bessel beams; artificial sur- face

Domains: Computer Science [cs]; Networking and Internet Architecture [cs.NI]; Engineering Sciences [physics]; Electronics

Walter Fuscaldo, Guido Valerio, Alessandro Galli, Ronan Sauleau, Anthony Grbic, et al.. Higher-Order Leaky-Mode Bessel-Beam Launcher. IEEE Transactions on Antennas and Propagation, 2016, 64 (3), pp.904--913. ⟨10.1109/TAP.2015.2513076⟩. ⟨hal-01331289⟩